Fastening clamp for connecting wooden parts

ABSTRACT

A mounting clamp for joining wooden parts to one another and to the foundation is used particularly for joining boards of outdoor balcony and deck covers. A rectangular, preferably square bottom plate is provided, and two vertical webs which are stamped out of the bottom plate in opposite directions in a U-shaped manner and are vertically bent are provided at a short distance next to each other in the center of the bottom plate relative to the width thereof. Each web supports a vertically projecting nail in the center, the nails extending in opposite directions.

The invention relates to a fastening clamp for connecting wooden parts to one another and to a foundation according to the preamble of Claim 1, as is used in particular for planks of balcony and terrace covers in the outdoors.

Connections of wooden parts with the goal of fastening two parallel planks to a foundation in the outdoors so that, on the one hand, an air gap and a space for working the wood are located between the planks and, on the other hand, an air gap—for air circulation and as a measure against rotting—are also located between the foundation and the planks, are known.

A spacer bracket is put between the planks in the longitudinal direction in current practice and narrow bracket parts are laid under the planks as the foundation, in order to achieve a typical spacing of at least 5 mm. The fastening is then performed using screws, using which the planks are fastened vertically through the support bracket parts on the foundation. The spacer brackets are subsequently removed. Notwithstanding the fact that the screws of the drilled-through planks are visible from above, the wood surface is frequently broken, so that cracks and projecting splinters form. Moisture penetrates via the holes and damages the wood, and the weather forms stains around the holes, which further worsens the already unattractive aesthetics of the screws. Finally, in long planks, widened areas arise around the screws, if the wood and the foundation have different longitudinal coefficients of expansion.

A connection system is known from U.S. Pat. No. 2,116,737, by which boards provided with tongue and groove joints are fixed to one another and to a foundation. A fastening clamp is used, whose vertical web has three nails protruding perpendicularly like claws on the top side, which penetrate into the plank faces. On the bottom web side, two angled soles which are bent down perpendicularly are provided, each approximately half of the web length, which are bent in opposite directions (left/right). To maintain the spacing and fastening on the foundation, a U-shaped rail which can be screwed onto the foundation is used, which fixes the clamp via lateral web shoulders, the holes resting on the legs of the rail. No spaces are provided between the boards by these known clamps, whereby no air circulation is possible and no shrinkage is taken into consideration, so that these clamps are not suitable for the outdoors.

A connection element is known from U.S. Pat. No. 441,227, which is usable for producing corner connections of crates. The clamp is manufactured from a metal strip, in which a tongue-shaped angled part is cut in a U-shape out of the strip as a vertical web and bent up perpendicularly. In addition, three corner tongues are formed as nails in the plate and in the web, which are hammered into the boards to be connected on the flat side. These known clamps are not suitable for a frontally externally invisible connection.

A fastening clamp is known from DE 102 30 797 C2, which is a double angle composed of two L-profiles and has an essentially inverted and/or recumbent T-cross-section. The double wall of the web does provide the advantage of increased strength of the web and support of the nails protruding from the two wall parts by the particular other wall part, in particular when driving in the clamps and/or nails. The spacing between the soles is at least double the plate thickness and can be correspondingly widened by a web head which can be provided in the outer part of the web, whereby good ventilation is made possible. Fastening holes are provided in the two angled soles, via which the clamps—and thus the planks—are fastenable on the foundation. In addition, support and spacing beads are introduced in the angled soles for better ventilation of the foundation, while downwardly protruding short cutter brackets, which engage in the support wood in the mounted state, are provided on the outer edges. These fastening clamps do represent a very well functioning, robust fastening element, but in particular due to the double wall of their middle web, they require a relatively large amount of material. The use of these clamps, which require a relatively large amount of material, is put into question from economic aspects due to the currently rapidly rising material costs, in particular for stainless steel.

The object of the invention is thus to disclose a fastening clamp of the above-mentioned species, which can be provided cost-effectively, while maintaining good handling ability and ensuring good air circulation between the wood parts, and a method for the simple, cost-effective production thereof. This object is achieved by a fastening clamp of the above-mentioned species having the features of Claim 1 and a method having the features of Claim 10. Advantageous designs are characterized in the particular dependent subclaims.

Accordingly, the fastening clamp according to the invention comprises a rectangular, preferably square soleplate, on which two vertical webs are provided centrally in the transverse extension at a slight distance in the longitudinal direction adjacent to one another. These webs are commonly punched out of the soleplate in a U-shape and bent vertically, i.e., by 90°. Each web carries a perpendicularly protruding, beak-shaped nail in the longitudinal middle and associated with its top side, each in opposing directions. The great advantage is thus achieved that a minimum of material is used, namely only one rectangular, preferably square sheet metal plate having an edge length of approximately 5 cm, for example, from which webs are cut out in a U-shape alternately in point symmetry and bent up perpendicularly. No additional material is thus required for the webs, but rather only parts and/or bent-up sections of the soleplate. At least one third to almost half of the material is thus saved in comparison to clamps having a double-walled web, which is reflected very significantly in the production costs.

The fastening nails situated in opposing orientation in the two webs are advantageously implemented and situated so that each web is preferably provided with only one nail, and centrally to the longitudinal extension thereof. The two nails, which protrude freely perpendicularly but in opposite directions from the two web faces, and also the clamps as a whole, as explained in greater detail hereafter, are offset laterally symmetric to a centrally provided symmetry point, i.e., the clamp sides are each identical, with offset by 180° of the clamp. Due to this point symmetry, the clamps do not have to be specially oriented during installation, so that automation of the installation is conceivable, in which the clamps are automatically supplied and may be installed using an impact or compressed air pressure device.

According to the invention, the nails are bent out from the web vertically, i.e., in a perpendicular plane in relation to the soleplate. If the fastening nail is additionally curved so it is open downward like a trough or arc, and tapers from the nail root to the tip, having a small radius at the tip, the nail shape is noticeably similar to a bird beak. The nail shape is thus practical, notwithstanding nature, and is extremely bending resistant over its entire length.

For additional reinforcement and simultaneous optimized guiding of the nails upon penetration into the wood, they may each be provided with a comb-shaped rib on their upper longitudinal side.

Instead of a rib, however, the nails may also have a notch-shaped groove in longitudinal central extension for the same purposes. Such grooves may also each be provided on the bottom side of the nails. Through the additional guiding of the nails thus obtained upon penetration into the wood, the installation is also made easier and twisting of the fastening clamps is prevented.

It is also particularly advantageous if the webs have a flattened corrugated profile in the plate longitudinal direction, whereby the two webs each have opposing bulges. The nails protrude from the particular flat base of the web U-profiles, and/or a nail protrudes centrally from each profiled web. In this way, a greater width and/or thickness of the web—and thus a greater distance between the planks—can be achieved. Thus, at a material thickness of only approximately 1.5 mm, for example, the width of the web profile can be 5 mm or significantly more, depending on the layout of the U-profile.

Notwithstanding the good air circulation thus also achieved through the web and/or along it, an optimum elasticity of the clamp is achieved, which has a very positive effect during shrinkage or swelling actions of the wood, because the clamp cooperates in some sense in such cases, i.e., may be elastically compressed or expanded. This is both because of the two parts of the web and/or the two webs, and also due to the corresponding web profiles.

Advantageous security against twisting of the installed clamps is achieved according to the invention in that a form fit with the foundation is formed via the soleplate, in that at least one claw-shaped cutter bracket which protrudes downward is formed and/or bent out of the soleplate. This cutter bracket may be provided as edge claws provided protruding on both longitudinal edges of the soleplate, which are drawn and/or bent at least 0.2 to 2.0 mm, preferably 0.5 mm, than the base bottom side of the profile recesses of the soleplate. Upon tightening of the fastening screws, these claw edges or cutter brackets, which protrude downward from the soleplate, also press into the support wood.

In order to additionally achieve traction in the direction of the board upon tightening of the fastening screws, an angled positioning of the fastening holes can also be provided by embossing. The screws may thus experience an inclination of 5-30°, preferably 10-20°, pointing away from the vertical webs.

The method for producing the previously described fastening clamp according to the invention essentially comprises V-shaped notches, which are offset to one another in the longitudinal and transverse direction and point in opposite directions, being introduced into a rectangular, preferably square plate, having an edge length of approximately 5 cm, for example, and the corresponding cutouts being formed as beak-shaped nails essentially perpendicularly and/or by 90° to the soleplate. A U-shaped notch is introduced in each case in the opposite direction around the nail tongues and bent down perpendicularly in the same pivot direction as the nail tongues, so that the nails are finally each located horizontally and thus parallel above the web cutout opening. It may be recognized that the fastening clamps allow a relatively simple punch-technology production in their basic embodiment.

It is advantageous if, during the production of the fastening clamp, U-profiles, which are implemented opposite to one another in the transverse direction and are situated adjacent to one another in the longitudinal direction, are first introduced in a downwardly depressed manner into the sheet metal forming the soleplate. A beak-shaped nail is then introduced into the flat base of a particular profile by corresponding punching and bending, after which the U-shaped cutouts are introduced just outside and parallel to the outer profile lines and the profile webs are pressed up correspondingly. Through these U-recesses or profiles, which are introduced in the first production step and extend in the transverse direction, on the one hand, the bending stiffness of the webs is increased and the web width and the spacing of the planks to one another are thus determined. On the other hand, a relatively small support and/or contact surface with the support wood is achieved by the particular recess or profile base, it also being ensured by the introduction of the screw holes into this profile area that only this relatively small area is brought into close contact with the support wood. In addition, it is ensured by the very close configuration of the screw holes to the particular longitudinal side of the soleplate implemented as a claw edge that the claw edges, which are drawn lower than the recess base, claw correspondingly into the support wood through the tightening of the screws.

The invention is explained in greater detail hereafter on the basis of exemplary embodiments with reference to the drawings.

In the figures:

FIG. 1: shows a perspective view of a fastening clamp in a first embodiment,

FIG. 2: shows a top view of the clamp according to FIG. 1,

FIG. 3: shows a section along line III-III from FIG. 2,

FIG. 4: shows a section along line IV-IV from FIG. 2,

FIG. 5: shows a top view similar to FIG. 1 of a second embodiment,

FIG. 6: shows a section along line VI-VI from FIG. 5,

FIG. 7: shows a top view similar to FIGS. 1 and 5 of a further embodiment,

FIG. 8: shows a section along line VIII-VIII from FIG. 7,

FIG. 9: shows a section along line IX-IX from FIG. 7, and

FIGS. 10 to 17: show a fastening clamp in various steps of the production method, each in a top view and in a frontal view.

It may be seen from FIGS. 1 through 4 that the fastening clamp according to the invention comprises a rectangular soleplate in a first embodiment, in which two vertical webs and 3 are provided in the central zone of the longitudinal extension adjacent to one another at a short distance. These vertically oriented U-profiles 4 and 5 each have a linear profile base 6, which are oriented parallel to one another in the longitudinal extension and to the longitudinal edges of the plate, having outwardly opening, relatively short legs 7 and 8. Leg extensions 9 and 10, which are essentially parallel to the longitudinal extension of the soleplate or at least point briefly in this direction, continue on the outer ends thereof in relation to the profile base 6, 7. The leg extensions 9 and 10 of one web are oriented aligned with the profile base 6 of the other web, so that the particular face of the leg extensions 8 and 9 and the profile base 6 pointing toward one or the other longitudinal edge 11 or 12 of the soleplate lie on the same line and thus form linear and also parallel supports for two planks 13 and 14 to be connected to one another. Depending on the layout of the depth of the U-profile 4, 5, the gap or spacing 15 between the planks can be determined precisely.

An essentially beak-shaped nail 16 and 17 protrudes perpendicularly to the web base 6 and simultaneously parallel to the soleplate 1 from the outer profile base surface of each web 2, 3, also in opposite extension, of course. In addition, they are central to the particular web and simultaneously close to the upper edge thereof. These nails 16, 17 are designed as longer than the height of the web, so that the correspondingly tapered nail cutout 18 below the nail occupies the entire height of the web below the nail and appears to lead further into the plate. An opening 20 may be recognized on the particular nail side of the webs 2, 3 in the plate 1, which is obtained by introducing a U-cutout or U-notch 21, whereby the contour of the particular web is cut out of the soleplate and subsequently the web is bent up perpendicularly. A recess 21 may be seen on the particular other side of the webs 2 and 3, which has the same U-profile viewed in longitudinal section as the particular webs. A hole 23 is introduced into the soleplate in each of these recesses 21, the particular outer edge of the recess being terminated rounded in relation to the hole so that upon introduction of a screw, the corresponding screw head rests unobstructed on the base of the recess 22 and allows proper contact pressure on the support wood.

In addition, it may also be seen from FIG. 1 in particular that the particular nail cutout 18, starting from the web, is led into the particular recess 22 so that the hole 23 and/or the corresponding concentric support surface for the screw head is not interfered with, but the effective extension of the two lower support surfaces of the recesses 21 is decreased. Secure fixing on the support wood 24 is possible through the two screw points, and simultaneously ventilation underneath over a very large area, as is recognizable in particular from FIGS. 3 and 4.

The longitudinal edges 11 and 12 of the soleplate are each bent downward and extend somewhat further down than the lower base surfaces 25 of the recesses 22. They form claw edges 26, which are longitudinally parallel to one another, as is recognizable from FIGS. 3 and 4 in particular. When the clamps are fastened pressed on and screwed tightly, having the base surface 25 pressed against the support wood 24, the claw edges 26 are pressed into the support wood 24 like blades, so that twisting, even in the event of fastening via only one screw, is prevented per se. In addition, the bending stiffness of the soleplate is increased by this angle bend.

The second embodiment shown in FIGS. 5 and 6 differs from the previously described embodiment according to FIGS. 1 through 4 solely in that the nails 16 and 17 have a comb-shaped rib 27 on their upper comb.

When forming the nails of 16, 17, they are provided with a central buckle, whereby the upper ribs 27 and notch-shaped grooves 35 on the bottom are formed simultaneously. The bending stiffness and penetration capability of the particular nail thus experiences an improvement.

In addition, an essentially L-shaped angle bend 30 is provided on the particular transverse edge 28 and/or 29, through which in particular the lateral zones, which are weakened by the U-opening or notches 20, 21, receive sufficient bending stiffness.

FIGS. 7, 8, and 9 show a fastening clamp similar to that in the preceding figures as a further embodiment, but here the nails 16, 17 have a notch-shaped groove 34 on their top side in central longitudinal extension, which is introduced by embossing. A groove 35 is simultaneously provided on the bottom side of the nail.

In addition, it may be seen how an embossing 31 is provided concentrically to the holes 23 for the fastening screws in each case, so that the axes 32 of the holes 23 are oriented at an angle α pointing away from the vertical webs 2, 3.

FIGS. 10 and 11 show a first section during the chip-free production of a fastening clamp according to the invention, the V-shaped nail cutouts 18 and 19 being shown in FIG. 10, which are introduced in opposing directions with point symmetry, while it may be seen from FIG. 11 how the nails 16, 17 corresponding to the cutouts 18 and 19 are pressed perpendicularly downward and implemented as beak-shaped. FIG. 12 illustrates how a profile recess 22 is associated with each of the nail cutouts 18, 19 and/or was introduced into the soleplate 1, in addition to a hole 23 in each case. FIG. 13 additionally shows how the U-recesses 22 project from the bottom side of the soleplate 1 and the nails 16 and 17 protrude from each of them.

FIGS. 14 and 15 show how, in a further step, a U-notch 21 is associated with each recess 22 and thus every nail 16, 17, and/or is introduced into the plate 1, the base of the U-notch 21 being situated close to the root of the nail cutout 18, 19. The parallel leas of the U-notch 21 are spaced apart from one another enough that they are provided outside the outer edges of the U-recesses 22, enclosing them in parallel approximately up to the middle of the transverse extension of the plate.

Finally, FIGS. 16 and 17 show how, in a last step, the U-cutouts 21 were bent down perpendicularly to the plate extension and in the same bending direction as the nails 16, 17, whereby the webs 2 and 3 are formed. Simultaneously or already in the preceding step, the longitudinal edges 11 and 12 were pressed downward and each formed a claw edge 26.

LIST OF REFERENCE NUMERALS

-   1 soleplate -   2 vertical web -   3 vertical web -   4 U-profile -   5 U-profile -   6 profile base -   7 profile leg -   8 profile leg -   9 leg end -   10 leg end -   11 longitudinal edge -   12 longitudinal edge -   13 plank -   14 plank -   15 spacing/gap -   16 nail -   17 nail -   18 V-cutout -   19 - -   20 (web) punch opening -   21 U-cutout -   22 recess -   23 hole -   24 support wood -   25 base surface -   26 claw edge -   27 rib -   28 transverse edge -   29 transverse edge -   30 angled bend -   31 embossing -   32 axis -   33 - -   34 upper groove -   35 lower groove 

1. A fastening clamp for connecting wooden parts to one another and to the foundation, in particular planks of balcony and terrace covers in the outdoors, having a vertical web, at least one tongue-shaped or beak-shaped nail, which protrudes perpendicularly from the web and is worked out therefrom, soles, which protrude perpendicularly on the bottom of the web, having at least one hole for fastening via screws, wherein a rectangular, preferably square soleplate (1) is provided, two vertical webs (2, 3) are provided at a slight distance adjacent to one another on the soleplate (1), centrally to the transverse extension thereof, which are punched out in opposite directions in U-shapes from the soleplate and are bent up vertically, each web (2, 3) centrally bearing a perpendicularly protruding nail (16, 17), each in opposing orientation.
 2. The fastening clamp according to claim 1, wherein the particular nail (16, 17) is punched out of the sole and web material and is bent down perpendicularly in the same bending direction as the web (2, 3) and points in the same direction as the web punch opening (20).
 3. The fastening clamp according to claim 1, wherein the webs (2, 3) each have opposing U-profiles (4, 5) to one another having open, relatively short profile legs (7, 8), the leg ends (9, 10) of one web being located in the same longitudinal extension as the linear U-profile base of the particular other web.
 4. The fastening clamp according to claim 3, wherein the particular profile provided symmetrically to the web center is provided running away from the web rear side as a recess (22) in the soleplate (1).
 5. The fastening clamp according to claim 4, wherein the hole (23) is situated in the recess (22), and thus in the opposite central extension to the web nail (16, 17).
 6. The fastening clamp according to claim 4, wherein an angularly directed embossing (31), which is at least semicircular, preferably at least in the form of a three-quarter circle, is provided at least in the size of the contact area of the screwheads in the recess (22), on the side pointing toward the vertical web (2, 3), concentrically to the hole (23), the axis (32) of the hole (23) being situated pointing away from the vertical web (2, 3) at an angle α of 5-30°, preferably 10-20°.
 7. The fastening clamp according claim 3, wherein the profile of the webs (2, 3) and soleplate is designed as center point symmetrical so that the particular profile base outer surface (6) of one web is located aligned in the longitudinal direction, i.e., at equal transverse spacing from the longitudinal center line of the clamp, as the axially-parallel U-leg extensions (9, 10) of the other web, so that in each case a plank support is provided on both web sides, and in each case on two leg extensions and one profile base.
 8. The fastening clamp according to claim 7, wherein the depth of the U-profile (4, 5) of the webs (2, 3) can be designed corresponding to the gap and/or spacing (15) to be provided between the planks (13 and 14) and from the planks (13, 14) to the support wood (24), e.g., at 5 mm spacing.
 9. The fastening clamp according to claim 1, wherein the two soleplate longitudinal edges (11, 12) parallel to the web longitudinal extension are bent downward (angled) so that they are drawn at least 0.2 to 2.0 mm, preferably 0.5 mm lower than the base bottom sides (25) of the profile recess (22), and form claw edges (26) which are longitudinally parallel to one another.
 10. The fastening clamp according to claim 1, wherein the nails (16, 17) situated close to the particular web top side have a nail length which is greater than the spacing of the nail root from the soleplate, so that the corresponding (nail) V-cutout (18) extends up into the sole recess (22) in the direction toward the screw through hole (23).
 11. The fastening clamp according to claim 10, wherein the nails (16, 17) have a comb-shaped rib (27) or a notch-shaped groove (34) on their top side in central longitudinal extension and have a groove (35) on their bottom side.
 12. A method for producing the fastening clamps according to claim 1, wherein V-cutouts (18), which are offset to one another in the longitudinal direction and transverse direction and point in opposite directions to one another, are introduced into a rectangular, preferably square soleplate metal plate and these cutouts are formed like beaks as tongues/nails (16, 17) pressed downward essentially perpendicularly (90°) to the plate (1), a U-shaped notch (21) is introduced in opposing directions around the nails and/or the notches (18) and bent up perpendicularly in the same clock direction as the nails (16, 17), so that the nails (16, 17) are subsequently each located horizontally and thus parallel above the web punch opening (20).
 13. The method according to claim 12, wherein, in the sheet metal forming the soleplate (1), firstly U-profiles, which are oriented and/or implemented opposite in the transverse direction and are situated adjacent to one another, are introduced as the recess (22) depressed downward, after which the beak-shaped nails (16, 17) are formed in the base of the profile by punching and bending and then the U-cutouts (21) are introduced at least slightly outside and parallel to the profile and the profile webs (2, 3) thus incised are bent out by 90°. 